Many portions of the human anatomy naturally articulate relative to one another. Generally, the articulation between the portions of the anatomy is substantially smooth and without abrasion. This articulation is allowed by the presence of natural tissues, such as cartilage and strong bone.
Over time, however, due to injury, stress, degenerative health issues and various other issues, articulation of the various portions of the anatomy may become rough or impractical. For example, injury may cause the cartilage or the boney structure to become weak, damaged, or non-existent. Therefore, the articulation of the anatomical portions is no longer possible for the individual.
At such times, it may be desirable to replace the anatomical portions with a prosthesis such that normal or easy articulation may be reproduced. A femur generally articulates within an acetabulum surface or cavity in a pelvis. After injury or other degenerative processes, the acetabulum may  become rough or damaged. Therefore, it may be desirable to replace the acetabulum with a prosthesis.
Various types of prostheses exist for the acetabulum. Over time, however, due to the nature of the articulation of the femur with the prosthesis, the femur may begin to apply a load to a rim of the acetabulum prosthesis. The application of a load to the rim may cause the acetabulum prosthesis to wear. Accordingly, it may be desirable to provide an acetabulum prosthesis for reducing rim loading.